Every step has decrease the amount of water but i can t get that last bit.
Water running down chimney breast in attic.
Broken or blocked gutters can cause rainwater to filter and collect in unwanted areas causing water ingress and damp in your chimney.
The slanted crown should provide a downward slope that will allow for water runoff.
If the stringer is un level water can travel a ways and even wind up at the chimney.
This can manifest in a number of ways such as.
3 exposed chimney brickwork gets damp and white lime deposits form on.
Is there any way water could still be getting down the flue due to gaps on cap.
This runs down and wets the timber leaving minerals they dissolved along the way.
Repeated wetting and evaporation has concentrated those seen here.
Further diagnostic inspection is needed.
1 water runs down the flue.
The chimney crown covers the top of the chimney to help protect it from the elements.
Efflorescence on a chimney might be just cosmetic as wind blown rain wets the chimney sides and leaches out mineral salts which remain white on the masonry surface of the chimney.
More on this later.
But efflorescence might also mean that water is running inside of the chimney flue or chimney structure.
Water could get into the attic or above your ceiling and either drip to the floor or roll along the stringer the long piece of wood that spaces out the roof trusses and runs the length of your house.
This portion of the chimney prevents water from entering the flue but also prevents wear and tear on the masonry.
If you have a broken gutter in heavy downpours water can run down the face of a wall and seep into any splits or cracks in mortar presenting as damp in your chimney breast.
Well the salts accumulated on the roof timbers are there due to years of tiny water ingress and condensation on the underside of the roof slates.
I still have a small bit a water coming down during occasional heavy wind and driving rain.